Participants will receive about three messages each week as well as occasional breaking-news alerts. While the messages are not personalized, the choice of topics is intended to coincide with each enrolled woman's stage in pregnancy and her child's age. For example, pregnant women can receive a six-message "starter pack" of tips.

Parents can sign up by texting "BABY" (or "BEBE" for messages in Spanish) to 511411. The service requires parents to share the baby's due date or date of birth and a zip code.

The better birth control

Teenage girls may prefer the pill, the patch or even wishful thinking, but their doctors should be recommending IUDs or hormonal implants — long-lasting and more effective birth control that you don't have to remember to use every time, the nation's leading gynecologists group said Thursday.

Both types of contraception are more invasive than the pill, requiring a doctor to put them in place. That, and cost, are probably why the pill is still the most popular form of contraception in the U.S.

But birth control pills often must be taken at the very same time every day to be most potent. And forgetting to take even one can lead to pregnancy, which is why the pill is sometimes only 91 percent effective.